Our objective is to achieve a major advance in the technology used to assess disability in children and youth. Measurement and practical requirements for identifying disability and evaluating individual progress across pediatric age groups and care settings present a serious dilemma to current fixed-item survey instruments. In Phase I proposals, we have developed a prototype computerized adaptive testing (CAT) application of mobility, self-care, and social function domains of the Pediatric Evaluation of Disability inventory (PEDI) called the PEDI-CAT that produces comparable scoring levels, precision, and responsiveness to change at significant reductions in respondent burden compared to full-length version of the current PEDI scales. Phase II work will improve the PEDI item pool by broadening the appropriate age range measured by each scale. Norm-based item calibrations for the PEDI functional scales (mobility, self-care, and social functioning) will be developed by collecting general population data for the new PEDI. Scoring algorithms and score reports will be created for a fully operational PEDI-CAT system. The full PEDI-CAT will be evaluated in terms of reliability, validity, and precision across score levels to create an operational system for the assessment of disability in children and youth that will dramatically improve measurement capabilities in clinical research and practice. SPECIFIC AIMS ARE TO: 1. Expand the original PEDI item pool in mobility, self-care and social functioning to incorporate functional tasks appropriate for children to 21 years of age;evaluate new items through expert feedback, cognitive testing and parent focus groups. 2. Develop final item calibrations and normative profiles for the revised functioning item pools by collecting responses from two large samples of caretakers for children 0-21 years: 1) a web-based nationally- representative normative sample (N=2,100);and 2) a web-based convenience sample of children with disabilities (N=600). 3. Create a fully operational PEDI-CAT system with norm- and criterion-based scoring and interpretive reports that can be administered on multiple platforms (e.g., desktop, via web);demonstrate the accuracy, precision, and reductions in respondent burden of the PEDI-CAT through real data simulation studies. 4. Confirm the validity and respondent acceptance of the PEDI-CAT by conducting a prospective study in a sample of children known to differ in disability status: receiving rehabilitation services (N=50) vs. not (N=50). A practical and feasible PEDI-CAT will greatly improve the information used in making decisions about disability status, service eligibility, program needs, outcomes of rehabilitation interventions and the effectiveness of clinical research. This new disability assessment will fill a critical void with a system that is more practical and precise, programmed to be fully operational on both desktop applications and on the Internet. PUBLIC HEALTH RELEVANCE This project addresses the need to measure self-care, social, and physical disability in children for outcomes management, individual status assessment with normative comparisons, or to assess the impact of interventions to minimize childhood disability. The product will capitalize on innovative software that will reduce the response burden on parents, children and clinicians, while providing accurate and precise information on functional status. This model of assessment using computerized adaptive testing will serve as a model for data collection on childhood disability in a variety of public health and research applications.